1. + Circles and Arcs Objective: To find the measure of central angles and arcs. To find circumference and arc length.

2. + Good Morning! Homework Check/Quiz Return Post Right Triangle DDM [19 points] Pre Circle DDM Notes: Circles and Arcs NONE. (Yes, you read that correctly.) Check Aspen and make sure you are not missing assignments from previous absences. AGENDAHOMEWORK

3. + Welcome to Unit 3! CIRCLES WAC Type 1: List 3 things you already know about circles. 1._________ 2._________ 3._________ http://padlet.com/alyssa_gage/circles

4. + Circles A circle is the set of all points equidistant from a given point called the center. You name a circle by its center. A radius is a segment that has one endpoint at the center and the other endpoint on the circle. A diameter is a segment that contains the center of a circle and has both endpoints on the circle.

5. + An arc is a part of the circle. A minor arc is smaller than a semicircle. A major arc is greater than a semicircle. A central angle is an angle whose vertex is the center of the circle.

6. + Semicircle One type of arc is a semicircle. The measure of a semicircle is 180 degrees. The measure of a minor arc is the measure of its corresponding central angle.

7. + Example #1

8. + Example #2

9. + Circumference Find the circumference of each circle. Leave your answer in terms of

10. + Arc Length The measure of an arc is in degrees while the arc length is a fraction of a circle’s circumference.

11. + Example #3-Finding Arc Length

12. + Example #4-Finding Arc Length

13. + Example #5 A P

14. + Arc Length and Area of a Sector Objective: To find circumference and arc length. To find area and the area of a sector.

15. + Recall from last class…

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20. + Sectors 1. Find what fraction of the circle is shaded. 2. Multiply the fraction shaded by the entire area of the circle. region bounded by an arc of the circle and the two radii to the arcs endpoints name by using one arc endpoint, the center of the circle, and the other arc endpoint

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